Where should we prioritize biodiversity conservation under climate change?

 

As most regions of the earth transition to altered climatic conditions, new methods are needed to identify the most likely refuges for biodiversity and to prioritize conservation actions. A variety of metrics and approaches have been proposed. Some are based on predicting future climates and rates of change (“climate velocity”). Others use only information on the current environment, finding areas where there are steep elevation gradients or topographic variation (“environmental diversity”) that help species to find climate refuges nearby. Faced with high stakes and a wide array of conservation targets, planners and land managers need new tools to deal with these new challenges.

In a new open-access paper published in Global Change Biology, led by Carlos Carroll and co-authored by U of A researchers Diana Stralberg, Scott Nielsen, and Andreas Hamann as part of the AdaptWestinitiative, we set out to compare a variety of velocity and diversity metrics for conservation planning under climate change across North America. Specifically, we evaluated similarities and differences among different methods across different spatial scales and elevation ranges. Not surprisingly, we found substantial variation among metrics. But somewhat remarkably given uncertainty around future climate change projections, there was more variation among environmental diversity metrics based on current environmental conditions than among climate velocity metrics based on alternative future climates. We also found that while all diversity and velocity metrics generally increase with elevation, so do the contrasts among them, due to interactions between climate and terrain (see figure below).

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So what is a planner to do, given all these differences? We suggest that metrics be combined, with areas of greater variation down-weighted (all spatial data are being made available through AdaptWest). Alternatively, finer-scale diversity metrics can be substituted where available, and supplemented with data on key target species as needed. Climate velocity metrics are useful for identifying broad-scale “macro-refugia,” where more species may find a long-term refuge from climate change. Areas of high environmental diversity should correspond with greater potential for local “micro-refugia” that can serve as temporary havens for species under a climate in flux. Where they coincide, short- and long-term conservation potential can be achieved most efficiently. We found that neither type was well-represented by the current protected area system, suggesting that much conservation work is still needed in order to prepare and adapt where possible to climate change.

D. Stralberg

Citation: Carroll, C., Roberts, D.R., Michalak, J.L., Lawler, J.J., Nielsen, S.E., Stralberg, D., Hamann, A., McRae, B.H., Wang, T. 2017. Scale-dependent complementarity of climatic velocity and environmental diversity for identifying priority areas for conservation under climate change. Global Change Biology (early view).

Link to paper: http://onlinelibrary.wiley.com/wol1/doi/10.1111/gcb.13679/abstract

Gain hands-on field experience, including working with wild animals!

Field course in Kananaskis: A unique opportunity to gain hands-on field experience, including working with wild animals! 

See the attached brochure for more information 

or

contact Stan Boutin (sboutin@ualberta.ca

or

attend an info session March 20 at noon-1pm or 21 at March 23 at 5-6pm. Both session will be held in CCIS 1-243

Enrolment is limited so register early

Hitching a ride with a carnivore: New paper from Boutin Lab

Hitching a ride with a carnivore

Research shows secondary seed dispersal by predator animals is important for recolonization of plants

Plants can’t move. That may seem like an obvious statement, but it has a lot of consequences for how plants live their lives and the kinds of adaptations that they have. Not being able to move is particularly problematic when they have offspring. For example, if a plant’s offspring grew next to the parent plant, the parent and offspring would probably end up competing with each other for space, water, and nutrients for the rest of their lives. So parent plants have to get creative in transporting their offspring elsewhere, even though the parents themselves cannot move. This movement away from the parent plant is called dispersal. Some plants have solved this problem by manipulating animals to transport their seeds. For example, their seeds could be contained within a fleshy, edible fruit that would then be eaten by a foraging animal. After the edible fruit was digested, the seeds could be deposited some distance away, thus solving the parent plant’s problem. Having seeds transported in this way comes with the added benefit that animal poop can be highly nutritious, which is great for a seedling just starting to grow. However, it’s pretty common that seeds don’t just germinate wherever they’re deposited: seeds are often transported by multiple animals or other means such as wind or water. For example, a cherry eaten by a bird could have its seed first deposited by the bird and then transported by ants where it then grows into a cherry tree.

We were interested in seed dispersal because this process can get quite bizarre. Many animals that eat seeds or fruit fall prey to predators. If the prey had recently eaten, they could still have seeds or fruit in their gut when they were killed by the predator. This means that the seeds that started out being eaten and then dispersed by one animal, ended up in the gut of a predator instead. In our cherry tree scenario, this could happen if the bird ate the cherry only to be consumed by a fox afterward. The cherry seed could then hitch a ride with the fox instead of the bird. The process of a seed being transported in the gut of multiple animals, such as first by a prey animal that was then eaten by a predator, is called  diploendozoochory.

Our paper was recently published in Ecosphere and is Open Access:

http://onlinelibrary.wiley.com/doi/10.1002/ecs2.1685/full

We wanted to know how widespread this phenomenon was and how important it was for plant populations. After reviewing scientific literature, we found that this kind of predator-assisted seed dispersal was first described by Charles Darwin in 1859. Since then, there have been other sporadic observations and we found that there is potential for this phenomenon to occur in many habitats and species. These studies showed that seeds consumed by prey that were eaten by predators may be moved greater distances than seeds deposited by the prey alone. Predators and prey may travel through different kinds of habitats, which means that seeds can end up in different places depending on who deposits them. Some seeds have particularly thick shells, which must be cracked open for the seedlings to grow. These plants can benefit from the wear and tear of passing through the guts of two animals, making them better able to germinate than if they had passed through the gut of the prey alone. It’s even possible that some plants have evolved specifically to take advantage of these predator-specific behaviours, in other words their seeds have evolved counting on the prey being eaten by a predator. However, these different factors are like pieces in a puzzle: to fully understand the big picture of how they affect plant populations, we need to know how all of these pieces fit together. So far, studies have only looked at small parts of the puzzle, and no study has put all of the pieces together to see the overall importance of this phenomenon for plant populations or its role in seed evolution.

Because predators may transport seeds somewhere different than prey, diploendozoochory has broader impacts than just affecting plant populations. For example, predators are often larger than their prey and can thus cover larger distances. As humans continue to fragment and alter wilderness, such as by cutting down forests or building roads, predators may be the only animals large enough to navigate across these areas and enable plants to recolonize them. Climate change will alter where some plants can find suitable places to grow, and seed-carrying predators could have a role in helping plants cover a larger area and hence move with the changing climate. On the other hand, plants that have been introduced to new countries and continents by humans, called introduced or invasive species, may invade new areas faster thanks to predators giving them a hand. Our work has highlighted how interesting and important this phenomenon is, and we hope that it will help and encourage others to fill some of these gaps in our understanding.

 

More info can be found here:

https://www.ualberta.ca/science/science-news/2017/february/secondary-seed-dispersal-by-predator-animals-is-important-for-recolonization-of-plants

 

South Rockies Grizzly Bear Progress Report (2006-2014)

A progress report for the South Rockies Grizzly Bear Project was recently released by Clayton Lamb and Garth Mowat.

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Notably, the authors document a 40% decline in grizzly bear populations in the South Rockies GBPU (North of Hwy 3) between 2006-2013, with very high and depensatory mortality rates, largely due to non-hunting mortality sources.

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The full report can be accessed by clicking the thumbnail below:

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Field Fun Friday

Today’s #FFF depicts the geographic extremes of the Rocky Mountain Range in British Columbia encountered by one of our crew this summer.  As biologists, we are very lucky to work in remote and beautiful landscapes while conducting research and these untouched landscapes provide motivation for the work we do as conservation biologists.

Summer in the Northern Rockies

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A fall day in the Southern Rockies- Flathead Valley, BC.

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